flours and the gluten complex

Question 1

what is flour?

Answer 1

derived from the endosperm of seeds or other starchy foods

Question 2

what is the most common source of flour

Answer 2

wheat

can also be obtained from oat, rye, barley, rice & corm

Question 3

do non cereal sources of flour exist?

Answer 3

yes,

soy, chickpea, potato, taro, arrowroot and coconut flour exist

Question 4

what is whole wheat flour composed of?

Answer 4

bran
germ
endosperm

Question 5

what is white flour composed of?

Answer 5

endosperm only

Question 6

what is bread flour composed of?

Answer 6

high gluten content

Question 7

what is durum (Semolina) flour composed of?

Answer 7

obtained from hard winter durum wheat

Question 8

what is all-purpose flour composed of?

Answer 8

gluten content in between cake and bread flours

Question 9

pastry and cake flours have what type of protein content?

Answer 9

lower protein content

Question 10

what is gluten flour?

Answer 10

it gets milled in a way to retain gluten.

Question 11

what does white flour result in?

Answer 11

produces breads with a higher volume
finer texture because of gluten forming proteins which develop more efficiently in the absence of germ and are responsible for viscoelasticity of wheat flour doughs.

Question 12

identify in increasing order gluten content of the following flours 
bread flour
pastry flour
cake flour
durum wheat flour
all purpose flour 
barley flour

Answer 12

barley
cake flour
pastry flour
all purpose flour
durum wheat flour
bread flour

Question 13

what flours are gluten free?

Answer 13

potato, soy, cornmeal, rice

Question 14

does triticale and rye flours contain gluten?

Answer 14

yes

rye is of lower gluten content but sill contains some

Question 15

what is the role of starch in flour?

Answer 15

strengtens through gelatinization

the dextrins contibute to color and sweetness

Question 16

a small, densely packed air cells results in what type of crumb?

Answer 16

fine

Question 17

large, irregular holes results in what type of crumb?

Answer 17

coarse

Question 18

how does gluten act in flour?

Answer 18

• it has elastic properties need for structure and allows bread to rise.
• it coagulates and sets when heated

Question 19

what proteins form the gluten complex in wheat flour?

Answer 19

gliadins & glutenin

Question 20

what do the gliadin chains looks like?

Answer 20

they are hydrophilic, single spherical polypeptide chains that fold onto themselves and are weakly bonded to each other.
fluid and sticky

Question 21

what do the glutenin chains looks like?

Answer 21

they are hydrophobic, longer than gliadin.
they form the largest component of gluten complex
they bond more strongly to each other
form strong s-s bond at the end of each chains
contributes to the elastic properties in dough

Question 22

what is the overall texture of gluten

Answer 22

elastic and plastic

Question 23

can vital wheat gluten be obtained? where is it used?

Answer 23

yes if you put dough under cold water, only the gluten product will be conserved.
it is used and added to products in the industry

Question 24

what does gluten control in dough?

Answer 24

it controls the rheological (flow) properties such as its stability

Question 25

what does gluten form?

Answer 25

a continuous, 3D network of hydrates proteins in which the starch granules are embedded

Question 26

what happens when gluten is hydrated

Answer 26

-air bubbles are distributed gliadin & gluetenin absorb 2x their weight in water and become gluten other proteins are part of the main dough results in a gluten complex with water in the spaces

Question 27

what happens to gluten when kneading?

Answer 27

- used extensively in bread making - expands the gluten strands - distributes the yeast - warm dough increases fermentation - distribution of co2

Question 28

what is the function of fat in dough?

Answer 28

coats gluten molecules and prevent clumping

Question 29

what is the role of sugar in dough?

Answer 29

sugar binds water and prevent gluten formation.

Question 30

what are the insoluble proteins in flour?

Answer 30

gliadin and glutenin

Question 31

what are some of the soluble proteins in flour?

Answer 31

``` albumin’globulin glycoproteins nucleoproteins lipid-protein complexes amylase & poroteases ```

Question 32

gluten is the general name given to what type of proteins?

Answer 32

storage proteins (prolamins/ peptide fractions)

Question 33

what protlamins are toxic for celiac disesase? in wheat in rye in barley

Answer 33

- gliadin - secalin - hordein

Question 34

what is xanthan gum?

Answer 34

polysaccharide that acts as a thickener and stabilizer | may also act as a binding agent in gluten free cooking

Question 35

what are some gluten substitutes?

Answer 35

``` guar gum psyllium husk chia sees flax seed meal gelatin agar agar ```